Advance RAVEL 0.6 development foundations

[epi13]

What changed

• Integrate reproducible candidate-001 development builds with frozen 0.5 provenance.
• Add compiled 0.6 behavioral and reverted-correction fixtures.
• Add tested retention transaction, memory lifecycle/retrieval, Forge boundary, and resource-placement foundations.
• Preserve frozen 0.4/0.5 bytes and document remaining evaluation boundaries.

Validation

• 25 Python unit tests
• GCC, Clang, and sanitizer candidate checks
• 0.6 provenance and behavioral targets
• baseline/training/unified and 0.4 checks
• frozen identity audit

0.6 remains development-only, unevaluated, unfrozen, unselected, and unpromoted.